Nature in the Heart of England: A personal view of nature at the junction of Oxfordshire, Warwickshire and Northamptonshire - also known as "Banburyshire". Sometimes further afield too!

Saturday, 27 December 2014

More on willow tits

My Christmas Eve sighting of a willow tit at Grimsbury Woodland nature reserve has inspired me to do a bit more research on their current and recent status in our area, and their conservation priority nationally.

willow tit, Grimsbury Woodland NR, 24th Dec. 2014

First of all, this species' national population has declined steeply since the mid 1970s. BTO Breeding Bird Survey data show a 83% decline in population between 1995 and 2012 The latest BTO Atlas shows a big contraction in range too, with the British population becoming increasingly restricted to the Midlands and immediately adjoining areas. In England it has pretty much gone from the south and is disappearing from east and west.

There are thought to be around 3400 pairs of willow tits in the UK. They have now become so scarce that the Rare Breeding Birds Panel collates records alongside long-standing rare breeders like black-necked grebes, hawfinches and hobbies. It is quite possible there are now fewer pairs of willow tits breeding in the BOS area than hobbies.

In our area, the decline has also be marked with wisespread disappearance from the southern half of the BOS recording area. From the 1960s to 1990s the willow tit was described as fairly numerous and very widespread. By the time "Birds of the Heart of England" was published in 2013, the willow tit's status had changed to scarce resident and notes that a few strongholds left north of Banbury. These include the wet scrubby woodlands around the canal feeder reservoirs at Wormleighton and Boddington, as well as the water supply reservoir at Grimsbury. It does feel that our area is currently in the "battle zone" for this bird, as it disappears from southern counties, but holds its ground in the Midlands.

Personally, I have recorded them occasionally from farmland hedgerows and copses in the Wardington and Cropredy area over the past twelve years, including a single bird visiting our garden feeders for a few days in the early noughties. I've also seen them on my Breeding Bird Survey site near Moreton Pinkney a couple of times in the past decade. But they certainly seem to be harder to find now than in the recent past.

In contrast, the very closely related marsh tit is still fairly numerous and likely to be encountered in any decent path of more mature woodland in our area. Both species are currently being recorded at Glyn Davies Wood BOS nature reserve, though marsh are certainly more common there than willow.

If you need a refresher on how to separate the two species have a look here or for even more detail here. The call of the willow tit is a very good field ID feature when heard well.

Marsh Tit, near Upper Wardington, Dec 2010

What might help us hang on to our willow tits? There has been quite a lot of research into the causes of decline, and a clear indication that continued provision of young, scrubby, wet woodland is what they really need. Deer grazing and lack of management can tip the balance and make a woodland less suitable habitat for them. They don't need big patches of woodland - overgrown hedgerows linking wet woodlands would be ideal. Some of our disused railway lines have been good for them in the past and could be a focus for future management for this species.

From this, my conclusion is that willow tit has to be in the top five
birds of conservation priority in Banburyshire. And there is
certainly a case for the top spot. It is also a bird that the BOS and others such as the Canal and Rivers Trust, Thames Water and many landowners can do much to help.